--- In cgs_synth@yahoogroups.com, frank death <maldoroar@...> wrote:
bending things ive done i learnt that wiring a potentiometer the wrong
way can cause pitch to go up when you turn anti-clockwise.
then zero pitch would have been at full clockwise rotation, rising as
I rotate the pot counterclockwise. IE the other way round to what the
pots in the other rows are doing. I haven't stuck a meter on it, but
it appears that rows A, C and D are putting out from 0v (pot fully
counterclockwise) to I think 5v (pot fully clockwise) whereas row B is
putting out 0v (pot fully counterclockwise) to -5v (pot fully
clockwise), so the pots on row B aren't reversed, they're acting
differently.
IIRC each opamp in an 072 inverts the signal going through it (maybe
someone more knowledgeable than I could confirm/deny this) so maybe
something's causing one of the opamps to not work properly? Casting
about a bit here TBH.
Otherwise, as mentioned, it works great. I left it running all night
last night to burn it in, no other problems evident. I took some
photos of the completed piece, and uploaded them to my flickr account:
http://www.flickr.com/photos/16804034@N00/2618961254/
http://www.flickr.com/photos/16804034@N00/2618138477/
http://www.flickr.com/photos/16804034@N00/2618139529/
http://www.flickr.com/photos/16804034@N00/2618140773/
I'll upload the .fpd file to the files section when I'm on my work
computer. A couple of notes - wiring everything off board was
necessary because of where I wanted the panel to go in my synthesizer,
and because it's a frac-rack panel, and there's not enough height in
that panel format. It is a COMPLETE pain in the ass though, and I
STRONGLY recommend attaching the pots to the boards, as per Ken's
instructions, and using a larger panel size. There are 18 wires per
step, plus a further 8 wires to solder in if you do it my way, which =
152 wires! Worth it, though.
>wrong way round? I haven't built this circuit but from a few circuit
> Have you wired the connections to the potentiometer (for pitch) the
bending things ive done i learnt that wiring a potentiometer the wrong
way can cause pitch to go up when you turn anti-clockwise.
> Of course i could be totally wrong as well.I would assume that if I'd wired the 8 pots in that row back-to front,
>
then zero pitch would have been at full clockwise rotation, rising as
I rotate the pot counterclockwise. IE the other way round to what the
pots in the other rows are doing. I haven't stuck a meter on it, but
it appears that rows A, C and D are putting out from 0v (pot fully
counterclockwise) to I think 5v (pot fully clockwise) whereas row B is
putting out 0v (pot fully counterclockwise) to -5v (pot fully
clockwise), so the pots on row B aren't reversed, they're acting
differently.
IIRC each opamp in an 072 inverts the signal going through it (maybe
someone more knowledgeable than I could confirm/deny this) so maybe
something's causing one of the opamps to not work properly? Casting
about a bit here TBH.
Otherwise, as mentioned, it works great. I left it running all night
last night to burn it in, no other problems evident. I took some
photos of the completed piece, and uploaded them to my flickr account:
http://www.flickr.com/photos/16804034@N00/2618961254/
http://www.flickr.com/photos/16804034@N00/2618138477/
http://www.flickr.com/photos/16804034@N00/2618139529/
http://www.flickr.com/photos/16804034@N00/2618140773/
I'll upload the .fpd file to the files section when I'm on my work
computer. A couple of notes - wiring everything off board was
necessary because of where I wanted the panel to go in my synthesizer,
and because it's a frac-rack panel, and there's not enough height in
that panel format. It is a COMPLETE pain in the ass though, and I
STRONGLY recommend attaching the pots to the boards, as per Ken's
instructions, and using a larger panel size. There are 18 wires per
step, plus a further 8 wires to solder in if you do it my way, which =
152 wires! Worth it, though.